Researchers at the University of Waterloo are working on a way to mass produce conjugated polymers, which conduct electricity and can be coaxed into being a semiconductor. The process sounds quite simple from The Inquirer's description, the polymers are created by dehydrating plastics which results in the poly(hetero)arenes currently used in products such as solar cells and LED displays. As the byproduct of this process is water, any device created using this technique would have a significantly lower environmental impact than traditional techniques though it is unclear what plastics could be dehydrated. There is a bit of the history of this process along with links to this specific research right here.

"Professor Derek Schipper and his team said it could soon be possible to mass produce semiconductors made from conjugated polymer, which is a type of plastic that can conduct electricity in a similar way to metals."